MKS INC. MKSI
COM · Common Stock · CUSIP 55306N104 · ISIN US55306N1046
Company in Andover, United States
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($75.6m this quarter). Holder counts are more reliable. Shares outstanding: 67.5m as of 2026-04-29, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $228.73. Options: 14 managers hold calls ($496.0m notional), 12 hold puts ($50.6m).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 357 |
| Q4 2022 | 316 |
| Q1 2023 | 325 |
| Q2 2023 | 321 |
| Q3 2023 | 324 |
| Q4 2023 | 325 |
| Q1 2024 | 343 |
| Q2 2024 | 397 |
| Q3 2024 | 410 |
| Q4 2024 | 419 |
| Q1 2025 | 399 |
| Q2 2025 | 397 |
| Q3 2025 | 435 |
| Q4 2025 | 516 |
| Q1 2026 | 621 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 223 | 148 |
| Q3 2024 | 244 | 163 |
| Q4 2024 | 215 | 181 |
| Q1 2025 | 223 | 197 |
| Q2 2025 | 224 | 205 |
| Q3 2025 | 225 | 176 |
| Q4 2025 | 284 | 185 |
| Q1 2026 | 354 | 244 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $201.8m | $25.2m | 0.12 |
| Q3 2025 | $261.2m | $44.3m | 0.17 |
| Q4 2025 | $339.9m | $58.0m | 0.17 |
| Q1 2026 | $496.0m | $50.6m | 0.10 |
Biggest buyers
| Aspex Management (HK) Ltd | New | +1.5m |
| Whale Rock Capital Management LLC | New | +1.3m |
| Capital World Investors | New | +1.3m |
| Point72 Asset Management, L.P. | Added | +984.5k |
| JPMORGAN CHASE & CO | Added | +544.9k |
| BlackRock, Inc. | Added | +502.9k |
| SAMLYN CAPITAL, LLC | New | +496.7k |
| CITADEL ADVISORS LLC | Added | +489.2k |
| FengHe Fund Management Pte. Ltd. | New | +456.3k |
| AQR CAPITAL MANAGEMENT LLC | Added | +419.8k |
Biggest sellers
| VICTORY CAPITAL MANAGEMENT INC | Reduced | -1.7m |
| Capital International Investors | Reduced | -1.3m |
| FMR LLC | Reduced | -1.3m |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -1.1m |
| COOKE & BIELER LP | Reduced | -756.7k |
| WELLINGTON MANAGEMENT GROUP LLP | Reduced | -718.9k |
| Southpoint Capital Advisors LP | Sold out | -600.0k |
| Madison Asset Management, LLC | Reduced | -583.1k |
| FRANKLIN RESOURCES INC | Reduced | -565.8k |
| Channing Capital Management, LLC | Reduced | -486.8k |
Biggest calls
| UBS Group AG | Added | $208.5m907.3k shares |
| JANE STREET GROUP, LLC | Added | $124.1m540.2k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $105.8m460.3k shares |
| PEAK6 LLC | Reduced | $23.0m100.2k shares |
| Caption Management, LLC | Unchanged | $14.9m65.0k shares |
| CITADEL ADVISORS LLC | Reduced | $7.1m31.1k shares |
| IMC-Chicago, LLC | Added | $5.5m23.9k shares |
| NOMURA HOLDINGS INC | Reduced | $3.3m14.5k shares |
| SIMPLEX TRADING, LLC | Reduced | $1.7m7.2k shares |
| Squarepoint Ops LLC | New | $988.2k4.3k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $17.8m77.4k shares |
| CITADEL ADVISORS LLC | Added | $12.8m55.7k shares |
| PEAK6 LLC | Added | $8.6m37.5k shares |
| NOMURA HOLDINGS INC | Reduced | $3.3m14.5k shares |
| JANE STREET GROUP, LLC | Reduced | $2.6m11.5k shares |
| IMC-Chicago, LLC | New | $1.6m7.0k shares |
| Squarepoint Ops LLC | New | $1.4m6.0k shares |
| Walleye Trading LLC | Reduced | $1.2m5.2k shares |
| TUDOR INVESTMENT CORP ET AL | New | $528.6k2.3k shares |
| Walleye Capital LLC | Added | $367.7k1.6k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| BlackRock, Inc. 13G · institution filed 2025-10-17 | 8.8% |
| Invesco Ltd. 13G · institution new · filed 2026-02-12 | 6.5% |
| VANGUARD PORTFOLIO MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 5.5% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 5.2% |
Fell to 5% or below in the last year: JPMORGAN CHASE & CO (2.9%, 2026-09-03), VICTORY CAPITAL MANAGEMENT INC (90.0%, 2026-07-24), FMR LLC (3.3%, 2026-05-06), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD PORTFOLIO MANAGEMENT LLC), PRICE T ROWE ASSOCIATES INC /MD/ (4.1%, 2026-02-17)
Insider purchases and sales in Q1 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q2 2024 | 0 | — | 1 | $68.8k | $68.8k |
| Q3 2024 | 0 | — | 3 | $276.4k | $62.8k |
| Q4 2024 | 0 | — | 2 | $92.9k | $92.9k |
| Q1 2025 | 0 | — | 3 | $889.4k | $53.2k |
| Q2 2025 | 0 | — | 1 | $24.5k | $24.5k |
| Q3 2025 | 0 | — | 4 | $1.1m | $1.1m |
| Q4 2025 | 0 | — | 3 | $182.9k | $182.9k |
| Q1 2026 | 0 | — | 11 | $18.3m | $71.8k |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-12 | Moloney Jacqueline F Director | Sold | $72.7k340 shares |
| 2026-03-06 | Taranto Eric Robert EVP & GM, VSD | Sold | $1.0m4.6k shares |
| 2026-03-02 | Mora Elizabeth Director | Sold plan | $71.8k300 shares |
| 2026-02-24 | COLELLA GERALD G Director · By The Gerald G. Colella 2019 Trust | Sold | $2.5m10.0k shares |
| 2026-02-24 | Schreiner James Alan EVP & COO | Sold | $1.0m4.1k shares |
| 2026-02-20 | Lee John Tseng-Chung President & CEO, director | Sold | $7.7m30.0k shares |
| 2026-02-20 | COLELLA GERALD G Director · By The Gerald G. Colella 2019 Trust | Sold | $2.5m10.0k shares |
| 2026-02-20 | Burke Kathleen Flaherty EVP, GC & Secretary | Sold | $1.1m4.3k shares |
| 2026-02-20 | Williams John Edward EVP & GM, PSD | Sold | $523.8k2.0k shares |
| 2026-02-20 | Henry David Philip EVP, Global Str Mktg & GM, MSD | Sold | $523.1k2.0k shares |
| 2026-02-20 | McCarthy Michelle M VP & Chief Accounting Officer | Sold | $366.5k1.5k shares |
| 2026-02-20 | Taranto Eric Robert EVP & GM, VSD | Sold | $359.6k1.5k shares |
| 2026-02-20 | CANNONE PETER III Director | Sold | $322.6k1.2k shares |
| 2026-02-20 | Moloney Jacqueline F Director | Sold | $205.2k829 shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.03% of their portfolio | 6.6m $1.5bn | Added +502.9k |
| Invesco Ltd. 0.08% of their portfolio | 3.7m $855.2m | Reduced -134.1k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.04% of their portfolio | 3.7m $847.0m | First filing |
| VANGUARD CAPITAL MANAGEMENT LLC 0.02% of their portfolio | 3.0m $692.7m | First filing |
| JPMORGAN CHASE & CO 0.03% of their portfolio | 2.1m $441.2m | Added +544.9k |
| STATE STREET CORP 0.02% of their portfolio | 2.1m $472.9m | Added +40.1k |
| Capital International Investors 0.11% of their portfolio | 2.0m $452.4m | Reduced -1.3m |
| FMR LLC 0.02% of their portfolio | 1.9m $444.4m | Reduced -1.3m |
| WELLINGTON MANAGEMENT GROUP LLP 0.08% of their portfolio | 1.8m $421.3m | Reduced -718.9k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.05% of their portfolio | 1.7m $390.7m | Reduced -1.1m |
| Point72 Asset Management, L.P. 0.64% of their portfolio | 1.6m $370.1m | Added +984.5k |
| GEODE CAPITAL MANAGEMENT, LLC 0.02% of their portfolio | 1.5m $353.8m | Added +285.3k |
| Aspex Management (HK) Ltd 5.13% of their portfolio | 1.5m $353.6m | New |
| NEUBERGER BERMAN GROUP LLC 0.25% of their portfolio | 1.4m $329.4m | Reduced -27.7k |
| Whale Rock Capital Management LLC 3.88% of their portfolio | 1.3m $300.3m | New |
| Capital World Investors 0.04% of their portfolio | 1.3m $293.5m | New |
| WESTFIELD CAPITAL MANAGEMENT CO LP 1.01% of their portfolio | 1.0m $240.6m | Added +207.0k |
| CITADEL ADVISORS LLC 0.15% of their portfolio | 947.0k $217.6m | Added +489.2k |
| MILLENNIUM MANAGEMENT LLC 0.15% of their portfolio | 894.4k $205.5m | Added +77.1k |
| VICTORY CAPITAL MANAGEMENT INC 0.13% of their portfolio | 878.8k $201.9m | Reduced -1.7m |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.03% of their portfolio | 866.6k $199.2m | Reduced -4.0k |
| DIMENSIONAL FUND ADVISORS LP 0.04% of their portfolio | 835.3k $191.9m | Reduced -282.1k |
| Bank of New York Mellon Corp 0.04% of their portfolio | 832.1k $191.2m | Added +43.5k |
| AQR CAPITAL MANAGEMENT LLC 0.06% of their portfolio | 616.5k $136.9m | Added +419.8k |
| PRINCIPAL FINANCIAL GROUP INC 0.08% of their portfolio | 614.2k $141.2m | Reduced -151.4k |
| NORTHERN TRUST CORP 0.02% of their portfolio | 569.2k $130.8m | Added +3.2k |
| MORGAN STANLEY 0.01% of their portfolio | 515.1k $118.4m | Reduced -75.5k |
| SAMLYN CAPITAL, LLC 1.96% of their portfolio | 496.7k $114.1m | New |
| FRANKLIN RESOURCES INC 0.03% of their portfolio | 475.9k $109.4m | Reduced -565.8k |
| BANK OF AMERICA CORP /DE/ 0.01% of their portfolio | 463.7k $106.6m | Reduced -16.5k |
| FengHe Fund Management Pte. Ltd. 14.49% of their portfolio | 456.3k $104.9m | New |
| UBS Group AG 0.02% of their portfolio | 432.1k $99.3m | Added +108.4k |
| VANGUARD FIDUCIARY TRUST CO 0.02% of their portfolio | 417.1k $95.9m | First filing |
| Balyasny Asset Management L.P. 0.18% of their portfolio | 407.4k $93.6m | Reduced -104.2k |
| ROYCE & ASSOCIATES LP 0.92% of their portfolio | 403.7k $92.8m | Reduced -212.9k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.08% of their portfolio | 400.3k $92.0m | Reduced -205.9k |
| Nuveen, LLC 0.02% of their portfolio | 378.2k $86.9m | Added +36.7k |
| Blue Grotto Capital, LLC 9.93% of their portfolio | 375.0k $86.2m | Reduced -40.5k |
| Contour Asset Management LLC 2.80% of their portfolio | 374.9k $86.1m | New |
| Madison Asset Management, LLC 0.96% of their portfolio | 338.3k $77.8m | Reduced -583.1k |
| RAYMOND JAMES FINANCIAL INC 0.02% of their portfolio | 338.0k $75.8m | Added +88.6k |
| TREMBLANT CAPITAL GROUP 2.44% of their portfolio | 329.8k $75.8m | New |
| NORDEA INVESTMENT MANAGEMENT AB 0.07% of their portfolio | 326.3k $71.5m | Reduced -273.5k |
| ALLIANCEBERNSTEIN L.P. 0.02% of their portfolio | 319.9k $51.1m | Added +233.8k |
| TimesSquare Capital Management, LLC 1.12% of their portfolio | 288.2k $66.2m | New |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC 3.00% of their portfolio | 282.2k $64.9m | Reduced -99.3k |
| AMERICAN CENTURY COMPANIES INC 0.03% of their portfolio | 281.0k $64.6m | Reduced -116.6k |
| TWO SIGMA INVESTMENTS, LP 0.05% of their portfolio | 278.7k $64.0m | Added +249.3k |
| NOMURA HOLDINGS INC 0.52% of their portfolio | 269.4k $61.9m | Reduced -94.7k |
| Quantinno Capital Management LP 0.10% of their portfolio | 259.7k $59.7m | Added +28.9k |
| Amundi 0.02% of their portfolio | 254.7k $58.5m | Added +114.5k |
| Penserra Capital Management LLC 0.68% of their portfolio | 250.6k $57.6m | Added +12.7k |
| Defiance ETFs, LLC 0.83% of their portfolio | 250.6k $57.6m | Added +12.7k |
| Park West Asset Management LLC 5.06% of their portfolio | 249.2k $57.3m | Reduced -29.4k |
| GOLDMAN SACHS GROUP INC 0.01% of their portfolio | 245.6k $56.4m | Added +65.6k |
| VALUE HOLDINGS MANAGEMENT CO. LLC 9.13% of their portfolio | 245.1k $56.3m | Reduced -52.7k |
| Harvey Partners, LLC 4.54% of their portfolio | 243.4k $55.9m | Reduced -45.8k |
| JANE STREET GROUP, LLC 0.06% of their portfolio | 243.3k $55.9m | Reduced -139.9k |
| WELLS FARGO & COMPANY/MN 0.01% of their portfolio | 243.0k $55.9m | Reduced -148.1k |
| SYSTEMATIC FINANCIAL MANAGEMENT LP 1.28% of their portfolio | 242.1k $55.6m | Reduced -22.7k |
| NATIXIS ADVISORS, LLC 0.07% of their portfolio | 232.0k $53.3m | Reduced -290.4k |
| JONES FINANCIAL COMPANIES LLLP 0.02% of their portfolio | 223.8k $49.9m | Added +221.6k |
| DENDUR CAPITAL LP 3.63% of their portfolio | 214.5k $49.3m | New |
| COOKE & BIELER LP 0.55% of their portfolio | 210.0k $48.3m | Reduced -756.7k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.01% of their portfolio | 203.9k $46.9m | Added +3.7k |
| Gotham Asset Management, LLC 0.14% of their portfolio | 195.4k $44.9m | Reduced -29.8k |
| Handelsbanken Fonder AB 0.15% of their portfolio | 192.5k $44.2m | Added +34.1k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.07% of their portfolio | 186.0k $42.7m | Added +35.3k |
| RHUMBLINE ADVISERS 0.04% of their portfolio | 180.0k $41.4m | Added +3.9k |
| Mizuho Markets Cayman LP 2.16% of their portfolio | 175.0k $40.2m | Unchanged |
| LPL Financial LLC 0.01% of their portfolio | 175.0k $40.2m | Added +163.1k |
| Ceredex Value Advisors LLC 1.23% of their portfolio | 169.5k $38.9m | Reduced -17.1k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.15% of their portfolio | 166.1k $38.2m | New |
| SORA INVESTORS LLC 3.44% of their portfolio | 162.8k $37.4m | New |
| BARCLAYS PLC 0.01% of their portfolio | 161.5k $37.1m | Reduced -178.8k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.38% of their portfolio | 161.2k $37.1m | Reduced -389.5k |
| SummitTX Capital, L.P. 1.18% of their portfolio | 160.9k $37.0m | Reduced -44.8k |
| Retirement Systems of Alabama 0.12% of their portfolio | 158.4k $36.4m | Added +1.7k |
| ROYAL BANK OF CANADA 0.01% of their portfolio | 153.0k $35.2m | Reduced -156.8k |
| Delta Global Management LP 2.84% of their portfolio | 151.1k $34.7m | Reduced -176.3k |
| BNP PARIBAS FINANCIAL MARKETS 0.02% of their portfolio | 148.7k $34.2m | Reduced -11.9k |
| CRAMER ROSENTHAL MCGLYNN LLC 2.50% of their portfolio | 148.4k $34.1m | Reduced -82.3k |
| Thrivent Financial for Lutherans 0.06% of their portfolio | 143.7k $33.0m | Added +56.1k |
| Polaris Capital Management, LLC 2.53% of their portfolio | 134.7k $31.0m | Reduced -130.4k |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 133.1k $30.6m | Reduced -926 |
| Swiss National Bank 0.02% of their portfolio | 132.9k $30.5m | Added +400 |
| LOOMIS SAYLES & CO L P 0.04% of their portfolio | 127.1k $29.2m | Reduced -57.1k |
| California Public Employees Retirement System 0.02% of their portfolio | 123.3k $28.3m | Added +8.9k |
| LIGHT STREET CAPITAL MANAGEMENT, LLC 5.65% of their portfolio | 122.3k $28.1m | Added +102.7k |
| D. E. Shaw & Co., Inc. 0.02% of their portfolio | 120.2k $27.6m | New |
| NEEDHAM INVESTMENT MANAGEMENT LLC 1.41% of their portfolio | 120.0k $27.6m | Reduced -10.5k |
| BESSEMER GROUP INC 0.04% of their portfolio | 117.9k $27.1m | Reduced -40.2k |
| BANK OF MONTREAL /CAN/ 0.01% of their portfolio | 117.1k $26.9m | Reduced -47.7k |
| Talos Eurisko Asset Management LP 4.48% of their portfolio | 114.0k $26.2m | New |
| SG Americas Securities, LLC 0.03% of their portfolio | 110.3k $25.4m | Added +91.2k |
| Daiwa Securities Group Inc. 0.07% of their portfolio | 107.3k $24.7m | Added +106.8k |
| RENAISSANCE TECHNOLOGIES LLC 0.04% of their portfolio | 103.6k $23.8m | New |
| SEI INVESTMENTS CO 0.02% of their portfolio | 101.2k $23.3m | Reduced -24.8k |
| FEDERATED HERMES, INC. 0.04% of their portfolio | 100.1k $23.0m | Added +812 |
| AMERIPRISE FINANCIAL INC 0.01% of their portfolio | 99.2k $22.8m | Reduced -43.3k |